When traveling a manipulator path, various actions are to be executed, frequently depending on the position on the path. By way of example, a welding current is to be switched on or off, an adhesive or paint nozzle is to be opened or closed, or a clamping fixture is to be opened or closed, at sections, in order to enable the passage of a manipulator-guided tool.
For this, it is known in the field to define switching points, referred to as switching path-points in the following, by means of a switching point routine, which includes a subroutine for executing the action, basically in the form:
. . .SLIN PTRIGGER WHEN PATH=abstand [:distance] DELAY=Zeit[:Time]DOUnterroutine[:Subroutine]SLIN Q. . .
A switching path-point is defined by this switching point routine TRIGGER, between the path points P and Q at a distance Abstand from the end pointQ of the section of the manipulator path defined as a Cartesian line by SLIN Q. When arriving at the switching path-point defined in this manner, after (or before, respectively, when Zeit<0) the time Zeit, the action defined by the subroutine Unterroutine is executed, e.g. a welding current is switched on, an adhesive or paint nozzle, or a clamping fixture, is opened.
When traveling along a defined manipulator path it may be necessary to retrace a section, e.g. after detecting a disruption in the process.
The disadvantage with retracing the path in this manner is that the switching point routines explained above are not executed. If, for example, a clamping fixture must be opened in order to enable the passage of a manipulator-guided tool, it is not automatically re-opened during the retracing of the path by the switching point routine—which only functions with respect to forward movement between points P and Q.
The object of the present invention is to improve a manipulator process.
This object is achieved by a method having the features of claim 1. Claim 7 places a means for executing such a method under protection. The dependent claims relate to advantageous further developments.